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Chapter 3.1
Pg. 41
Factors Affecting Climate
The Sun and Latitude
 Weather
is the conditions of the atmosphere at a
given time and place. Weather conditions over a
given time are the climate of that region.
 The tilt of the Earth and the Sun make differences
in weather and climate.
Continued
 When
the Sun’s energy hits Earth about half is
reflected back. Earth’s surface absorbs the other
half. The measurement of heat is called
temperature.
 Earth’s atmosphere traps heat energy in a process
called the Greenhouse effect.
Continued
 Evidence
shows that Earth has gotten warmer in
recent decades. Called Global Warming and most
scientists believe it is caused by humans.
 Burning coal, natural gas and oil adds carbon
dioxide to the lower atmosphere. Carbon dioxide
absorbs heat. Reducing production of carbon
dioxide could help with stopping global warming.
 Some people do not believe in Global Warming.
Atmospheric Pressure
 Air
Pressure
 The higher you go the less air you have pressing
down on you.
 Low pressure areas also occur when the air is
heated.
 Low pressure usually accompanies unstable
weather conditions.
Continued
 Cold
air is dense and sinks toward Earth’s surface.
Creates a high pressure area. Air sinks it heats and
dries and causes high pressure.
 4 major air pressure zones. Equatorial low,
subtropical highs, subpolar lows, ad the polar
highs.
Global Wind Belts
 Wind
is the horizontal flow of air. Flows from
high to low pressure.
 Move heat and cold across earth.
 Winds that flow in the same direction most of the
time are prevailing winds.
 Doldrums are around the equator and there is not
much wind.
Oceans and Currents
 Water
heats and cools more slowly than land, land
near the ocean do not have such great temperature
ranges as areas in the interior of continents.
 Great Rivers of seawater, called currents, are also
important to climate.
 Gulf Stream flows north along the U.S. east coast
is a warm current.